I was hesitant to watch DS9 at first after enjoying TNG, however, I was easily hooked.
For me, I liked the darker tone, the story arcs and the conflict between characters that showed their flaws.
I also think it’s aged better than TNG.
For me it's a reasonable alternative for the rest of us who know that we would never be "top of our class" of the " youngest person to ever such and such".
Or just realizing that all of Starfleet and the federation can't be stationed on the Enterprise.
It's where those of use that graduated or whatever could reasonably actually be that's in space.
Sure you could end up on a planet getting to study exciting new plants or animals, if you're in to that but really, it's still just a planet. It rains more or it rains less, there are this and that plant or animal, it's still just a planet.
The station is out in space. Even if it's not moving to some other boring planet each week or month or year, you get to see all the
Alien people interacting, you'd get meet all sort of different people.
Generally you're not in emminent danger every other week (except summers)
For me the show is my comfort place.
I'd have loved to live there.
Way more interesting than a typical Star fleet station, less "military" walking around more regular people getting up to no good.
Etc.